Apparatus for making debris-free nail collation

ABSTRACT

An apparatus for forming a plastic molded collated fastener assembly includes a conveyor for carrying a plurality of fasteners in a horizontal plane defining an upper surface and a lower surface, a preheater for preheating the plurality of nails and a plastic collation molding station. The molding station includes injection nozzles for applying molten plastic to the upper surface of the fasteners and to the lower surface of the fasteners. The station further includes forming wheels including a holding section to, in cooperation with the conveyor, secure the fasteners. The wheels include a forming section to mold the molten plastic to the fasteners to form a collation having a collar encircling the fasteners&#39; shanks and a connecting portion extending between the collars. The apparatus includes at least one cooling spray nozzle to spray a cooling vapor onto the fasteners and collations and at least one cooling spray nozzle to spray a cooling vapor onto the forming wheels. An air chiller further cools the collations.

BACKGROUND OF THE INVENTION

The present invention pertains to debris-free fastener collations. Moreparticularly, the present invention pertains to an apparatus for makinga debris-free collated nail strip formed with a plastic material for usein a fastener driving tool.

Fast-acting fastener driving tools are in widespread use in theconstruction industry and used in industries ranging from pre-fabricatedhousing construction to luxury residential, commercial and industrialconstruction.

The nails that are used in these tools are assembled in strips that areinserted into a magazine. There are two principal nail strip or nailcollation formations—paper tape and plastic. As the name suggests, papertape collations maintain the nails in a strip by using a strip of tapethat is adhered to one or both sides of the arranged nails. Plasticcollations use a formed or pre-formed collar-type element to secure thefasteners to one another and parallel in the strip form.

Paper tape has certain advantages, one of which is ease of manufacture.In addition, paper tape collations, which use a glue or adhesive toadhere the tape to the fasteners, tend to be quite rigid, butsufficiently easy to separate one fastener from an adjacent fastener, aswhen the fastener is driven from the tool into a substrate. Whilerigidity on the one hand is good for the collation in that it reducesthe opportunity for strip corrugation, on the other hand, it tends torequire additional force to separate the fastener from the strip.Moreover, paper tape collations also produce a significant amount ofdebris when the fastener is separated from the strip. This debris cancause increased tool maintenance as well as jamming and increaseddown-time for tool repair.

Plastic collations use a collar that is molded to or fit around theshank of the fasteners. The collars are connected by bridges that breakor separate to permit the fastener to be separated from the strip. Onedrawback to commonly available plastic collations is that the collation,although molded around the fastener, is nevertheless only superficiallyaffixed to the fastener. That is, although the fastener is supportedwithin and by the collation, the fastener can be rotated within thecollar. It may not be loosely held, but can nonetheless be rotated. Thishas two ramifications.

First, because the fasteners are loosely supported, the collation can beoverly flexible. This can result in increased corrugation of the stripin the tool magazine. Second, because the plastic is only looselyaffixed to the fastener, it has been observed the plastic collars andbridges fracture as the fastener is driven into the substrate. This hasbeen shown to result in the generation of debris, and in certaininstances substantial amounts of debris. At times, it has also beenfound that the collars collect under the fastener head, thus preventingthe fastener from being driven fully into the substrate. This may thusrequire a user to then drive, by hand, e.g., with a hammer, the fastenerthe remainder of the way into the substrate. Another drawback to theknown plastic collations was that because the collation material wasquite brittle, the downstream collation fractured, causing fasteners tobecome off-centered in the tool, which resulted in tool jams andmisfires.

In an effort to eliminate the drawbacks associated with the generationof debris and the accumulation of material under the fastener head, andoff-centered driven fasteners, a debris-free fastener was developed thatuses an adhesive-modified chemistry for the plastic collation materialin conjunction with preheating the fasteners prior to application(molding) of the collation.

It was found that the improved, debris-free collation generatedsignificantly less debris and that the plastic collation materialadhered well to the fastener shank. As a result, the plastic materialentered the substrate as the fastener was driven from the strip into thesubstrate. Such a fastener collation is disclosed in Shelton, U.S.patent application Ser. No. 11/383,032, filed May 12, 2006, Shelton,U.S. patent application Ser. No. 11/734,684, filed Apr. 12, 2007, andHeskel, U.S. patent application Ser. No. 11/935,541, filed Nov. 6, 2007,all of which are commonly assigned with the present application and areincorporated herein by reference.

While the above-noted fastener collations overcame many of the drawbacksin prior fastener collations, they were found to be very difficult tomanufacture. Using known manufacturing devices and techniques resultedin too much flow of the collation material and thus mis-formedcollations, sticking of the collation material to the forming molds, andother manufacturing obstacles.

Accordingly, there is a need for an apparatus for forming a plasticcollation system for strip-formed fasteners. Desirably, such anapparatus provides a high quality collation formed on the fasteners.More desirably, such an apparatus uses portions of known extruders toapply adhesive-modified materials for the plastic collation. Moredesirably still, such a collation forming apparatus provides a highspeed process with little to no waste or rejection of product. Mostdesirably, such a device is used to form a plastic collation formulatedfrom an adhesive polymer such as a polyolefin, such that when thefastener is driven from a driving tool, the collar portion remainsadhered to the fastener so that the collar portion penetrates thesubstrate with the fastener.

BRIEF SUMMARY OF THE INVENTION

An apparatus is configured to form a plastic molded collation onfasteners having a shank, a head and a tip. The fasteners are carried ona conveyor, at least in part, in a horizontal plane that defines anupper surface and a lower surface of the fastener collation assembly.The collation so formed does not use a paper tape. That is, it is apaper tape-less collation.

The apparatus includes a preheater for preheating the plurality of nailsand a plastic collation molding station. The station includes injectionnozzles, preferably two nozzles, one for applying molten plastic to theupper surface of the fasteners and the other nozzle for applying plasticto the lower surface of the fasteners.

The collation station further includes upper and lower forming wheels(preferably two sets to form two sets of collations) that each include aholding section to, in cooperation with the conveyor, secure thefasteners and a forming section to mold the molten plastic to thefasteners to form the collations. Each collation has a collar encirclingthe fasteners' shanks and a connecting portion extending between thecollars.

The apparatus includes a cooling spray nozzle to spray a cooling vaporonto the upper surface of the fasteners and collations, and a coolingspray nozzle to spray cooling vapor onto the lower surface of thefasteners and collations. The apparatus also includes at least onecooling spray nozzle to spray a cooling vapor onto the forming wheels(preferably at about the 12 o'clock position prior to engaging thefasteners).

The apparatus also includes air coolers or chillers to provide a chilledair stream over the fasteners.

In a present forming apparatus, the injection nozzles are disposedproximal to the upper and lower surfaces of the fasteners.

One or more temperature sensors can be disposed at the nozzles. Atemperature sensor can be disposed to monitor the temperature of thefasteners following the preheater.

Hold-downs are positioned at the forming wheels to maintain thefasteners in the conveyor, in the horizontal plane and engaged with thelower forming wheel as the fasteners traverse between the formingwheels.

In a present apparatus the forming wheels are adjustably mounted to oneanother to permit some variation in the angle of the fasteners relativeto the direction of travel through the apparatus. One adjustablemounting configuration includes a stub fixedly mounted to one of theforming wheels that is received in an opening in the other (itsadjacent) forming wheel. The stub is resiliently received in the formingwheel to provide a small amount of movement of the wheels relative toeach other. Resilient elements such as o-rings disposed on the stubs canprovide the resilient interface of the wheels.

In a present apparatus the forming wheels are internally cooled. Thewheels include internal cooling channels supplied by a shaft on whichthe forming wheels rotate. As such, the shaft includes internal coolingchannels in flow communication with the internal cooling channels in thewheels.

The apparatus can include one or more fastener aligning elementsdisposed to align the fasteners head to head and/or tip to tip, withinthe plane. The aligning elements can be disposed prior to andimmediately following the plastic collation molding station.

These and other features and advantages of the present invention will bereadily apparent from the following detailed description, in conjunctionwith the claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The benefits and advantages of the present invention will become morereadily apparent to those of ordinary skill in the relevant art afterreviewing the following detailed description and accompanying drawings,wherein:

FIG. 1 is a plan view of an exemplary nail collation formed inaccordance with a method of the present invention;

FIG. 2 is a schematic illustration of an apparatus for carrying out thepresent method;

FIGS. 2A and 2B are partial illustrations, as indicated in FIG. 2, ofthe apparatus and method carried out thereby;

FIG. 3 is a partial, enlarged view of fasteners being positioned in asingulating and conveying apparatus for preparing the fasteners forpositioning within the collation forming apparatus;

FIG. 4 is a view of the apparatus of FIG. 3 as seen from an oppositeperspective;

FIG. 5 is a front view of the apparatus showing the fasteners beingpositioned on a conveyor and showing both an alignment wheel and afastener angle sensing station;

FIG. 5A is a view taken along line 5-5 showing the fasteners aligned inthe conveyor (lying on the conveyor bands);

FIG. 6 is a perspective (front) view of the collation forming machineshowing the fastener preheating station;

FIG. 7 is a perspective (front) view of the forming wheels shown in adisengaged state and illustrating the polymer injectors disposed aboveand below the plane along which the fasteners are conveyed;

FIG. 8 shows the wheels in the closed or engaged state with the coolantvaporizers operating to spray vaporized water onto the fasteners;

FIG. 9 is an illustration of the fasteners secured in and engaged by theforming wheels;

FIG. 10 is a sectional view taken along line 10-10 of FIG. 9;

FIG. 11 is a perspective (front) view of the collation forming machineshowing the gas (air) cooling station;

FIG. 12 is a perspective (front) view of the cutting station showing thecutting blade moving down to engage a portion of a fastener strip;

FIG. 13 is a view similar to FIG. 12 showing the blade section pivotingto move with the strip as the cut is made;

FIG. 14 is a perspective (front) view of the turning plate for movingthe cut strips onto a second portion of the conveyor and showing anejection paddle in the extended (ejection) state;

FIG. 15 is an opposite side view of the turning plate and showing astrip of fasteners moving onto the second portion of the conveyor;

FIG. 16 is a top view of the nail strip on the second portion of theconveyor, as indicated at 16-16 in FIG. 15;

FIG. 17 is a perspective illustration of the tip coating preheater;

FIG. 18 is a perspective illustration of the tip coater;

FIG. 19 is a perspective (front) view of the end of the conveyor(downstream of the tip coating station);

FIG. 20 is a perspective (front) view of the conveyor and stacker;

FIG. 21 is a partial sectional view of the forming wheel shaft;

and

FIGS. 22A-D are partial sectional views of the forming wheels and shaft,as taken along lines 22A-22A through 22D-22D.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in variousforms, there is shown in the drawings and will hereinafter be describeda presently preferred embodiment with the understanding that the presentdisclosure is to be considered an exemplification of the invention andis not intended to limit the invention to the specific embodimentillustrated.

It should be further understood that the title of this section of thisspecification, namely, “Detailed Description Of The Invention”, relatesto a requirement of the United States Patent Office, and does not imply,nor should be inferred to limit the subject matter disclosed herein.

Referring now to the figures and in particular to FIG. 1, there is shownan exemplary nail strip 10 having a plastic collation system 12 formedthereon. The collation 12 is as disclosed in the aforementioned U.S.Patent applications to Shelton et al. and Heskel et al. In theillustrated strip 10, the nails 14 are positioned parallel to oneanother (e.g., with their axes A₁₄ parallel) and at an angle a of about20 degrees to the transverse direction (as indicated at 16) of the strip10. Other angles α (including zero degrees) are, however, contemplated.The nails 14 can be full head nails, D-head (or clipped head) nails orany other type of nail.

As discussed above, the nails 14 are collated and held to one another bythe plastic collation 12. The plastic collation 12 is molded to, overand around the shanks 18 of the nails 14, and connects each nail 14 toits adjacent nail or nails (that is, extends between the nails 14). Thecollation 12 is formed as a contiguous molding around and between thenails 14; nevertheless, for purposes of this disclosure, the molding,indicated generally at 20, is viewed as having a collar portion 22,which is that portion that encircles the nail shank 18, and a connectingportion 24, which is that portion that extends between and connectsadjacent collar portions 22. The collation 12 so formed does not use apaper tape. That is, it is a paper tape-less collation 12. Upper andlower moldings or collations 20 are shown that are formed with structuresimilar to one another. The structure can, however, be different fromthe upper to the lower collations.

As set forth above and in the aforementioned patents to Shelton et al.and Heskel et al., the present nail collation 12 differs from previouslyknown plastic collations in a number of important aspects. First, ratherthan the plastic merely encircling and extending around and between thenails, the present collation 12 uses a material that is molded (orformed) around and adheres to the nails. It has been found that plasticthat is adhered to the nails, rather than merely molded around the nailsis advantageous in that the plastic material tends to remain on the nailshank during driving. That is, the collation 12 material is maintainedon the shank 18 as the nail 14 penetrates the substrate and thus entersthe substrate with the nail. Advantageously, much less debris isgenerated during driving of a nail from the present nail strip comparedto prior known nail strips.

In addition, adhesion of the plastic material to the nails 14 also hasbenefits vis-à-vis the rigidity of the nail strip 10. That is, when theplastic merely encircles the nail shanks, the plastic can slip aroundthe nail shanks. On the other hand, by adhering the plastic molding tothe shanks, the nail strip tends to become more rigid and is less likelyto flex and to corrugate.

A present material is an adhesive polymer, such as an adhesivepolyolefin, such as a maleic anhydride modified polyolefin, such aspolypropylene, polyethylene or the like. Other suitable materials, suchas epoxies, other resins, such as a polyvinyl alcohol (PVA) basedmaterial, an ethylene vinyl alcohol (EVA) based material, anacrylonitrile butadiene styrene (ABS) based material, ionomers, methylmethacrylates and the like. Fillers can also be used as can blends ofany of the materials, as suitable. Other materials will be recognized bythose skilled in the art and are within the scope and spirit of thepresent invention.

In forming the collation 12, the nails 14 are first surface conditionedto enhance adhesion. Conditioning is first carried out by washing thenails in a caustic solution. The solution is a mildly acidic ironphosphate solution or a mildly alkaline solution. It was found that sucha solution conditions the surface of the steel for adhesion with theplastic.

The conditioned nails are then fed into a collation forming machine orapparatus 26. The machine 26 includes, generally, a conveyor 30 toconvey the nails 14 along and through various stations, including apreheating station 42, a collation forming station 43, a cooling station100, a cutting station 102, a tip coating station 114 and a stacker 122.One or more drives 101, such as motors, drive the conveyor 30 andcomponents at other driven stations. The machine 26, of course includesa controller 103 for controlling the overall operation of the machine26.

The nails 14 are conveyed through a chute 28 and singulated prior topositioning on the conveyor 30. A present conveyor 30 is formed as twocontinuous bands 36, 38, each having a plurality of spaced apart grooves40 formed therein, much like a saw blade. The bands 36, 38 rotateopposing one another in loops with one side of each loop 36 a, 38 aparallel and nearest to the opposing side of the other loop. Thefasteners (nails 14) are carried in the grooves 40 opposite one anotheras the two loops rotate, thus carrying the nails 14 in a flat(horizontal) plane P along a straight path through the collation formingmachine 26. The bands 36, 38 are movable relative to one another toadjust the angle a at which the nails 14 lie in between the bands 36,38.

The nails are positioning into a conveyor 30 at a preselected angle thatis the same as angle a, which in a present machine 26 and strip 10, is22 degrees. The nails 14 are positioned on the conveyor 30 and alignedso that the tips 32 and heads 34 are all aligned with one another. In apresent conveyor 30, the nails 14 are supported above and below (oroutside of) the location at which the collations 12 will be formed. Thatis, the nails 14 are supported closer to the tips 32 and heads 34. Analigning element 35 aligns the nails head-to-head with one another. Itwill be appreciated that the aligning element could be configured toalign the nails 14 tip-to-tip. The angle a is measured by an angularmeasurement device 37 downstream of the aligning element 35.

The nails 14 are then conveyed to the preheater 42 where they arepreheated. A preheat temperature of about 500 deg. F. to about 620 deg.F. is a suitable range, and a preferred temperature is about 600 deg. F.for use with the maleic anhydride modified polypropylene. Othertemperatures may be better suited for other materials. Preheating iscarried out using flame heating, however, induction heaters or any othersuitable heating medium and method may be used. Heating is controlled bya sensor 44 (e.g., an infra-red sensor) immediately downstream of theheaters 42. In a present collation forming apparatus, upper and lowerheaters 42 a,b are used to heat the nails 14 from above and from belowto provide more consistent and even preheating.

As seen in FIGS. 7-10, the nails are then conveyed to the collationforming station at which a pair of forming wheels 46, 48 are configuredto carry and embrace the nails 14 and to mold the plastic (collations12) between the nails 14 and grooves 50 formed in the wheels 46, 48.Accordingly, the plastic is introduced to the nails 14 immediately priorto the nails 14 entering the nip 52 between the wheels 46, 48. To effectplastic introduction or flow, a nozzle 54 is positioned above the nailsand another nozzle 56 is positioned below the nails 14, just prior tothe forming wheels 46, 48. The plastic is carried by the nails 14 intothe space between the wheels 46, 48.

Plastic flow rate and temperature (from the nozzles 54, 56) are bothcontrolled to effect proper collation 12 formation. The plastic flow iscontrolled by the controller which controls the extruder (not shown)that supplies the plastic (that is the plastic feed), and by a gate orvalve 58 (one shown) at the nozzles 54, 56. Sensors 57 in the nozzles54, 56 monitor the temperature at the nozzles 54, 56. The plastic flowsfrom the extruder exit to the nozzles 54, 56 through piping, tubing orconduit 60. In that the plastic is highly viscous, even though theextruder stops, plastic continues to flow from the extruder to thenozzles 54, 56. The valves 58 are configured to stop the flow of plasticbut are also configured to prevent the build up of pressure at thenozzles 54, 56 (which could otherwise result in a shock of plastic whenopened). As such, both a “shock” of plastic (upon resuming flow) and adrool of plastic (following isolation) are avoided. In this manner, flowis better controlled and waste is reduced.

Temperature of the plastic is also tightly controlled by heaters 62located in the nozzles 54, 56. In this manner, the plastic is introducedto the nails 14 within a range of about 400 deg. F. to 440 deg. F., andpreferably about 410 deg. F. Control of the plastic temperature at thenozzle 54, 56 (tip) also prevents the plastic from freezing (hardening)at the tip 64, thus interrupting the collation forming operation.

At the exit of the wheels (as indicated at 66 in FIG. 8), the plastic ishot and is still in a flowable state. In order to stabilize thecollation 12, it is desirable to freeze the plastic—actually to cool theplastic—to a point such that an outer skin or layer is formed and isstable, although the plastic under the outer layer may still be in aplastic or flowable state. As such, the plastic is cooled by a spray ofchilled water vapor at the exit 66 of the wheels 46, 48. As shown inFIG. 8, vapor spray nozzles 68 are located to spray water vapor V downonto the top surface 70 (as seen in Fla 9) and up onto the bottomsurface 72 of the collation 12 as it exits the forming wheels 46, 48, tobetter and more evenly cool the plastic collation 12 and facilitatecuring.

It has also been found that in order for the wheels 46, 48 to properlyconform the plastic 12 to the shape of the grooves 50 (in the wheels 46,48), and to release the plastic from the wheels 46, 48 without sticking(at the exit 66), a spray of chilled water vapor is applied to thewheels 346, 48. In a present method, a vapor spray is applied onto theupper wheel 46 from an upper spray nozzle 74 at a point prior to thewheels 46, 48 engaging the plastic 12 and the nails 14. In a presentarrangement, the water vapor is applied to the wheels at the apex of thewheels' path (e.g., the 12 o'clock position); however, the exactlocation can be varied to effect a desired machine configuration.

In addition to externally cooling and lubricating the forming wheels 46,48 (with the vapor spray 74), the wheels 46, 48 are cooled internally.As seen in FIG. 21-22A-D, cooling channels 76 are formed in the wheels46, 48 to maintain the wheels 46, 48 at a desired temperature. Thecooling channels 76 are fed through channels 78 formed in the shaft 80about which the wheels 46, 48 rotate. Seals 82 are positioned on theshaft 80 to maintain a seal between the rotating wheels 46, 48 and thestationary shaft 80. A liquid, preferably water is introduced into theshaft channels 78, flows into and through the wheels 46, 48 and out fromthe wheels 46, 48 through the channels 78 in the shaft 80. Cooling isprovided independently to each wheel 46, 48 through respective channels78 in the shaft 80. Other cooling fluids are, of course, contemplated bythe present invention.

The wheels 46, 48 are of a novel design. There are four wheels, whichinclude an upper 46 and a lower 48 wheel for each of the two collationsformed on the nails 14. The upper and lower wheels 46, 48 act in concertin forming each of the collations 12.

The wheels 46, 48 include a holding portion or groove 84 and a formingportion or groove 86. The nail 14 is held or secured in the holdingportion 84, while the forming portion 86 has a slightly larger sizegroove and is that portion of the wheel 46, 48 in which the plasticforms (flows) around the nail 14. Essentially, the forming portions 86of the upper 46 and lower 48 wheels form a mold cavity to form thecollar 22 and connecting portions 24 of the collation 12. That is, thereis sufficient space between the forming portions 86 (of the upper andlower wheels 46, 48) and the nail 14 to form the plastic collation 12(the collar portion 22 of the collation 12), and sufficient spacebetween the peaks 88 of the forming portions 86 to form the connectingportions 24 of the collations 12. The holding portions 84 are located,relative to the forming portions 84, to effect a desired collationprofile. That is, if it is desired to form the collar 22 concentric withthe shank 18, then the holding portion 84 is centered with the formingportion 86 (as seen in FIG. 10). Conversely, if it is desired to formthe collar 22 eccentric relative to the shank 18, then the holdingportion 84 is offset relative to the forming portion 86. In a presentmethod, the holding portion 84 is centered relative to the formingportion 86 so that the collar 22 and shank 18 are concentric.

The wheels 46, 48 are also configured to allow some variation in theangle a of entry of the nails 14. It will be appreciated that the nails14 are mass produced consumables and that the operating speed of themachine must be such that the collations 12 are formed at very highspeeds. As such, although a desired angle (e.g., 20 degrees) is set bythe various operations on the nails 14, there may be some slightvariation in the angle (up to about +/−2.5 degrees) in which thecollation is within acceptable tolerances. In order to accommodate thattolerance, and still provide an acceptable collation, the forming wheels46, 48 are permitted to move (rotate) relative to one another with asmall degree of freedom, and to allow some measure of misalignment ofthe nails 14 on the conveyor 30 relative to the wheels 46, 48.

As seen in FIG. 22B, the upper wheels 46 a,b and the lower wheels 48 a,bare mounted to one another by a stub 90 that extends between the wheels(e.g., 46 a,b). The stub 90 is rigidly mounted to one of the wheels(e.g., 46 a), but is mounted to the other wheel (e.g., 46 b) with aresilient element 92 (such as an O-ring) fitted on the stub 90 which isfitted into an opening 94 in the wheel 46 b. This provides the smalldegree of relative movement (or freedom) between the wheels 46 a,b. Inthis manner, if there is a small variation in the angle of the nails(within tolerances of course) as they enter the wheels 46, 48, the nails14 continue to move through the wheels 46, 48 without mishap. It will beappreciated that if the nails are rigidly held by the wheels, the nailscan, if the angle is slightly off, wedge into the wheels or not fitwithin the grooves, resulting in a failed collation, machine shut downand related time and material costs.

As the nails 14 move through and beyond the forming wheels 46, 48 theyare held down on the conveyor 30 by a pair of hold down rails 96. Theserails 96 do not apply any significant pressure on the nails 14, but holdthem down on the conveyor 30 to prevent the nails 14 from lifting withthe wheels 46 (as they exit the wheels) or from lifting as the plastic12 cools and cures. Shortly downstream of the vapor spray cooling 68,the rails 96 end and the nail collations are continued in the conveyor30.

At this point in time, the outer layer of the plastic has begun toharden or cure, but the material between the outer layer and the body ofthe nail, although highly viscous, is still in a formable state. A siderail 98 is positioned downstream of the hold-down rails 96 to (axially)align the fasteners tip-to-tip or head-to-head. Typically any adjustmentin the alignment is minimal, if needed at all, but can be done with thecollation material in this state.

A further cooling step is carried out using air coolers 100 to force agas, preferably chilled air, over the nails 14. Following the coolingstep, the collations are sufficiently cooled and cured to be cut intostrips 10 of a predetermined length or number of nails 14. The nailstrips 10 are cut at a cutting station 102 that includes a cutter blade104 that is mounted to a reciprocating carriage 106. The carriage 106 isalso configured to pivot (as at 108) so that the cut can be effected onthe moving strip 10 (that is, without slowing or stopping the strip). Abiasing element 110, such as a spring returns the carriage 106 (and thusthe cutter blade 104) to the home position following the cut.

Once cut, the nail strips 10 have a tip coating applied. Prior tocoating, the nail tips 32 are heated, such as by the illustrated flameheater 112. Induction heaters or the like, as suitable, may also beused. The coating is then applied. The coating enhances or easespenetration of the nails 14 into a substrate, and can also enhance theholding power of the nails 14. The coating can be applied by conveyingthe nails 14 through a tip coater 114 that includes, for example, a pairof rotating foam rollers 116, 118, one of which 116 is positioned in areservoir 120 of the coating material (liquid). Following coating anddrying, the nail strips 10 are then stacked for packaging at a stacker122.

It will be appreciated that although certain specific details, forexample plastic temperature ranges, preheat temperatures and the likeare provided, these specific details are those for use with the notedmaleic anhydride modified polypropylene and it is anticipated that thespecific temperatures and the like will vary for other materials.

All patents referred to herein, are incorporated herein by reference,whether or not specifically done so within the text of this disclosure.

In the present disclosure, the words “a” or “an” are to be taken toinclude both the singular and the plural. Conversely, any reference toplural items shall, where appropriate, include the singular.

From the foregoing it will be observed that numerous modifications andvariations can be effectuated without departing from the true spirit andscope of the novel concepts of the present invention. It is to beunderstood that no limitation with respect to the specific embodimentsillustrated is intended or should be inferred. The disclosure isintended to cover by the appended claims all such modifications as fallwithin the scope of the claims.

1. An apparatus for forming a plastic molded collated fastener assemblycomprising: a conveyor for carrying a plurality of fasteners, thefasteners having a shank, a head and a tip, the conveyor carrying thefasteners, at least in part, in a horizontal plane defining an uppersurface and a lower surface; a preheater for preheating the plurality ofnails; a plastic collation molding station including injection nozzlesfor applying molten plastic to the upper surface of the fasteners and tothe lower surface of the fasteners, the plastic collation stationfurther including forming wheels including a holding section to, incooperation with the conveyor, secure the fasteners and a formingsection to mold the molten plastic to the fasteners to form a collationhaving a collar encircling the fasteners' shanks and a connectingportion extending between the collars, at least one cooling spray nozzleto spray a cooling vapor onto the fasteners and collations and at leastone cooling spray nozzle to spray a cooling vapor onto the formingwheels; and a cooler to cool the collations.
 2. The apparatus forforming a plastic molded collated fastener assembly in accordance withclaim 1 including upper and lower forming wheels.
 3. The apparatus forforming a plastic molded collated fastener assembly in accordance withclaim 1 including an injection nozzle disposed proximal to the uppersurface of the fasteners and an injection nozzle disposed proximal tothe lower surface of the fasteners.
 4. The apparatus for forming aplastic molded collated fastener assembly in accordance with claim 3including one or more temperature sensors at the nozzles.
 5. Theapparatus for forming a plastic molded collated fastener assembly inaccordance with claim 1 including a temperature sensor to monitor thetemperature of the fasteners following the preheater.
 6. The apparatusfor forming a plastic molded collated fastener assembly in accordancewith claim 2 including hold-downs disposed at the forming wheels tomaintain the fasteners disposed in the conveyor, in the horizontal planeand engaged with the lower forming wheel as the fasteners traversebetween the forming wheels.
 7. The apparatus for forming a plasticmolded collated fastener assembly in accordance with claim 2 includingtwo upper and two lower forming wheels.
 8. The apparatus for forming aplastic molded collated fastener assembly in accordance with claim 7wherein the upper forming wheels are adjustably mounted to one anotherand wherein the lower forming wheels are adjustably mounted to oneanother.
 9. The apparatus for forming a plastic molded collated fastenerassembly in accordance with claim 8 wherein the adjustable mountingincludes a stub fixedly mounted to one of the upper forming wheels and astub fixedly mounted to one of the lower forming wheels and openings inthe other of the upper forming wheel and the lower forming wheel forreceiving the respective stubs, the stubs being resiliently received inthe others of the upper and lower forming wheels.
 10. The apparatus forforming a plastic molded collated fastener assembly in accordance withclaim 9 including resilient elements disposed on the stubs forinterfacing with the openings in the forming wheels.
 11. The apparatusfor forming a plastic molded collated fastener assembly in accordancewith claim 1 wherein the forming wheels are internally cooled.
 12. Theapparatus for forming a plastic molded collated fastener assembly inaccordance with claim 11 wherein the forming wheels include internalcooling channels supplied by a shaft on which the forming wheels rotate,the shaft including internal cooling channels in flow communication withthe internal cooling channels in the wheels.
 13. The apparatus forforming a plastic molded collated fastener assembly in accordance withclaim 1 including a fastener aligning element disposed to align thefasteners head to head and/or tip to tip, within the plane.
 14. Theapparatus for forming a plastic molded collated fastener assembly inaccordance with claim 13 wherein the fastener aligning element isdisposed prior to the plastic collation molding station.
 15. Theapparatus for forming a plastic molded collated fastener assembly inaccordance with claim 14 including a second fastener aligning elementdisposed after the plastic collation molding station.
 16. The apparatusfor forming a plastic molded collated fastener assembly in accordancewith claim 1 including at least two cooling spray nozzles wherein atleast one cooling spray nozzle is directed to spray a cooling vapor ontothe upper surface of the fasteners and at least one spray nozzle isdirected to spray a cooling vapor onto the lower surface of thefasteners.
 17. The apparatus for forming a plastic molded collatedfastener assembly in accordance with claim 1 wherein the forming wheelcooling spray nozzle is disposed at about a 12 o'clock position forspraying the cooling vapor onto the forming wheel.
 18. The apparatus forforming a plastic molded collated fastener assembly in accordance withclaim 1 wherein the molten plastic includes a heat activated adhesivecomponent and wherein the preheater supplies heat sufficient to activatethe heat activated adhesive.
 19. The apparatus for forming a plasticmolded collated fastener assembly in accordance with claim 1 includingone or more valves at the injection nozzles to permit and to stop theflow of molten plastic from the injection nozzles.
 20. An apparatus forforming a plastic molded collated fastener assembly comprising: aconveyor for carrying a plurality of fasteners, the fasteners having ashank, a head and a tip, the conveyor carrying the fasteners, at leastin part, in a horizontal plane defining an upper surface and a lowersurface; a preheater for preheating the plurality of nails; a plasticcollation molding station including upper and lower injection nozzlesfor applying molten plastic to the upper surface of the fasteners and tothe lower surface of the fasteners, the plastic collation stationfurther including upper and lower forming wheels including a holdingsection to, in cooperation with the conveyor, secure the fasteners and aforming section to mold the molten plastic to the fasteners to form acollation having a collar encircling the fasteners' shanks and aconnecting portion extending between the collars, the forming wheelsbeing internally cooled; upper and lower spray nozzles to spray acooling vapor onto the upper and lower surfaces, respectively, of thefasteners and collations and at least one cooling spray nozzle to spraya cooling vapor onto the upper forming wheel; hold-downs disposed atabout the forming wheels to maintain the fasteners disposed in theconveyor, in the horizontal plane and engaged with the lower formingwheel as the fasteners traverse between the forming wheels; and a coolerto cool the collations.
 21. The apparatus for forming a plastic moldedcollated fastener assembly in accordance with claim 20 including twosets of forming wheels to form two sets of collations.
 22. The apparatusfor forming a plastic molded collated fastener assembly in accordancewith claim 20 including fastener aligning elements disposed to align thefasteners head to head and/or tip to tip, within the plane, the fasteneraligning elements being disposed prior to and following the plasticcollation molding station.
 23. The apparatus for forming a plasticmolded collated fastener assembly in accordance with claim 20 whereinthe molten plastic includes a heat activated adhesive component andwherein the preheater supplies heat sufficient to activate the heatactivated adhesive.
 24. The apparatus for forming a plastic moldedcollated fastener assembly in accordance with claim 20 including one ormore valves at the injection nozzles to permit and to stop the flow ofmolten plastic from the injection nozzles.
 25. An apparatus for forminga plastic molded collated fastener assembly comprising: a conveyor forcanying a plurality of fasteners, the fasteners having a shank, a headand a tip, the conveyor carrying the fasteners, at least in part, in ahorizontal plane defining an upper surface and a lower surface; meansfor preheating the plurality of nails; a plastic collation moldingstation including injection nozzles for applying molten plastic to theupper surface of the fasteners and to the lower surface of thefasteners, the plastic collation station further including formingwheels including a holding section to, in cooperation with the conveyor,secure the fasteners and a forming section to mold the molten plastic tothe fasteners to form a collation having a collar encircling thefasteners' shanks and a connecting portion extending between thecollars; means cooperating with the holding section to secure thefasteners at the forming wheels to maintain the fasteners disposed inthe conveyor, in the horizontal plane and engaged with the lower formingwheel as the fasteners traverse between the forming wheels; at least onecooling spray nozzle to spray a cooling vapor onto the fasteners andcollations and at least one cooling spray nozzle to spray a coolingvapor onto the forming wheels; and a cooler to cool the collations. 26.The apparatus for forming a plastic molded collated fastener assembly inaccordance with claim 25 including aligning means for aligning thefasteners tip to tip and/or head to head.
 27. The apparatus for forminga plastic molded collated fastener assembly in accordance with claim 26wherein the aligning means is disposed prior to the preheating means.28. The apparatus for forming a plastic molded collated fastenerassembly in accordance with claim 27 including further aligning meansdisposed after the plastic collation molding station.
 29. The apparatusfor forming a plastic molded collated fastener assembly in accordancewith claim 25 wherein the molten plastic includes a heat activatedadhesive component and wherein the preheater supplies heat sufficient toactivate the heat activated adhesive.
 30. The apparatus for forming aplastic molded collated fastener assembly in accordance with claim 25including one or more valves at the injection nozzles to permit and tostop the flow of molten plastic from the injection nozzles.